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- Gong, J, et al.
(författare)
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Tubing loops as a model for cardiopulmonary bypass circuits : both the biomaterial and the blood-gas phase interfaces induce complement activation in an in vitro model.
- 1996
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Ingår i: Journal of Clinical Immunology. - 0271-9142 .- 1573-2592. ; 16:4, s. 222-223
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Tidskriftsartikel (refereegranskat)abstract
- We describe here a model for the study of blood/surface and blood/air interaction as encountered in cardiopulmonary bypass (CPB) circuits. Polyethylene tubing was filled with serum or blood and closed end to end into loops whereby the volume of the remaining air bubble was inversely varied with respect to that of the fluid. The loops were rotated vertically in a water bath at 37 degrees C. The profiles of C3a, iC3, and TCC generation were similar to those observed at surgery, involving CPB. Soluble heparin and heparan sulfate inhibited both C3a and TCC formation, but surface-conjugated heparin had only a minor effect. Binding of C3 and/or C3 fragments to the heparin surface was much reduced compared to the amine matrix to which heparin was linked, but compared with the polyethylene surface the effect was less pronounced. These data suggest that, in addition to the biomaterial surface, the blood-gas interface seems to play an important role in the activation of complement and that this activation is inhibitable by high concentrations of soluble glucose aminoglycans.
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| 4. |
- Nordin Fredrikson, Gunilla, et al.
(författare)
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Expression of properdin in complete and incomplete deficiency: normal in vitro synthesis by monocytes in two cases with properdin deficiency type II due to distinct mutations
- 1998
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Ingår i: Journal of Clinical Immunology. - 0271-9142. ; 18:4, s. 272-282
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Tidskriftsartikel (refereegranskat)abstract
- Three properdin deficiency phenotypes have been reported--complete deficiency (type I), incomplete deficiency (type II), and dysfunction of properdin protein (type III)--all associated with increased susceptibility to meningococcal disease. Expression of properdin by monocytes was examined in type I deficiency and in two unrelated cases with type II deficiency, one from a Swedish and one from a Danish family. The properdin gene in the Danish family contained a point mutation in exon 8 causing a Gln316-->Arg substitution, distinct from a point mutation in exon 4 previously found in the Swedish family. Both genes coded for physicochemically abnormal properdin molecules with changed hydrophilicity. Monocytes from all the properdin-deficient individuals produced properdin mRNA in a normal fashion. In type I deficiency no intracellular or secreted properdin was found, indicating rapid intracellular degradation. Monocytes from the males with type II deficiency expressed and secreted properdin normally. Properdin in sera with type II deficiency showed abnormal oligomerization with a relative decrease in properdin trimers and tetramers. Our findings suggest that the low concentration of circulating properdin in type II deficiency is caused by increased extracellular catabolism. Analysis of properdin expression by monocytes in a female carrier in the family with properdin deficiency type I provided direct evidence of lyonization at the cellular level.
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